Spark-plug.



W. S THOMAS.

SPARK PLUG, APPLICATION FILED JUNE 13. 1916.

Patented Jan. 22, 1918-.

WILLIAM ,S. THOMAS, OF LOCK HAVEN, PENNSYLVANIA.

SPARK-Piece Specification of Letters Patent. Patented Jan. 22,

Application filed June 13, 1916. Serial No. 103,384.

To all whom it may concern:

Be it known that I, WILLIAM S. THOMAS,

citizen of the United States, residing at Lock Haven, in the county of Clinton and State of Pennsylvania, have invented ce tain new. and useful Improvements in Spark- Plugs, of which the following is a specifica- My invention consists of an improved. form of spark plug of the type used .on internal combustion engines. to produce the spark for exploding the gas within the cyli'nder. One object of my invention is to prothe electrodes is also operative to position the parts in order to provide an opening through which cleaning fluid may be inserted to clean the inner parts thereof.

A further object is to so construct my invention that the several parts thereof will efficiently operate for a long period of time without requiring their removal .for cleanmg. a 4

A still further object of my invention is to so reinforce an insulating element of my invention that the latter will not tend to corrode, fracture, or shorten the electric circuit.

A still further object is to so construct my invention that the electrodes may be adjusted into different positions to suit the requirements of the engine without removing any of the elements from the plug proper.

Another object of my invention is to provide a spark plug in which the parts may be .quickly and easily assembled or removed, and which will be durable and can be manufactured at a reasonably low cost.

.These objects, and other advantageous ends which Will be'dcscribed hereinafter, I

attain in the following manner, reference being which Figure 1 a side elevation of my inven-' tion. r

Fig. 2 is a topplan view of Fig. 1.

v Fig. 3 is an enlarged sectional QlQVfitlOIl'l of my invention showing the parts in the operative position occupied during the normal running of the engine.

had to the accompanying drawings in nature to Fig. 3

Fig. 4 is a fragmentary View of similar showing several of the parts moved into a position for admitting cleaning fluid.

Fig. 5 is a sectional plan view on the line (171a of Fig. 3 drawn on an enlarged scale, an

Fig. 6 is a longitudinal elevation of an insulating member which I employ.

Referring to the drawings, 1 represents a metallic body portion having a screwthreaded end 2 which is provided with a cavity 3 which extends from the lower end 4. This cavity 3 is reduced in diameter as shown at 5, and thereby provides an annular shoulder or ledge 6. This reduced portion 5 extends from the shoulder 6 'to the outer upper surface 7 of the body portion 1.

An insulating member 8 is provided with an annular flange 9 which produces a shoulder 10 on its upper face for engagement with the lower flanged end 11 of a metallic tube or jacket 12. The body portion 13 of the insulating member 8 fits within the jacket 12, and is cemented thereto, so that while there is no lateral pressure against the body portion 13, .the cement will hold the member 8 within the jacket and also act to prevent any moisture from effecting the porcelain within said jacket.

The flanged end 11 is of smaller diameter than the diameter of the cavity 3, so that a space 14 is always present, however, the upper shoulder 15 of the end. ll-abuts the shoulder 6 and normally forms a seal between the cavity 3 and the reduced open" ing 5.

The reduced opening 5 is of larger diameter than the jacket 12, and thus provides an annular space 16 around said jacket, this space being in communication with the atmosphere. The upper end of the jacket 12 is screiv thi'eaded at 17, and a threaded sleeve 18 is designed to be screwed upon said threaded end. This sleeve 18 is provided with a transversely extending slot 19 through which passes a tightening screw 20, the latter being provided with screw-threads and designed to fit within a tapped opening 21 in the lower portion of the sleeve 18 and freely pass through an opening 22 in the upper portion provided by said slot 19, so that an inward movement of said screw 20 will tend to move the upper portion 23 of the sleeve 18 toward. the lower portion 24 of said sleeve, and thereby jam the threaded portion of the sleeve and the threaded portion 17 of the jacket, preventing relative movement between said sleeve and the jacket.

The jacket 12 terminates at 25, preferably at a slight distance above the uppermost surface of the sleeve .18, and the porcelain body 13 extends bcyo'ndthe jacket as at 26 and is provided with a tubular cover of flexible rubber 27 which normally projects slightly above the upper end of the body portion 13 of the porcelain member 8, and is designed to be engaged by a screw-threaded washer 28 which is adjustably mounted on a screw-threaded binding post 29, the latter beingsecured within a portion 26 of the porcelain member 8, so that when this threaded washer is'screwed into engagementwith the upper end of the tubular cover, the latter will be compressed longitudinally and form a positive seal between the threaded washer 28 and the end 25 of the jacket 12, thus eifectively preventing moisture or foreign material from engaging the outer surface of the porcelain which projects beyond I the tube 12.

A binding 'nut 30 is screwed on the upper most portion of the binding post 29, and between this' nut and the washer may be secured the one end of the electric conduit or wire.- v

A wire 31 is embedded within the central portion of the porcelain 8, and at its upper end engages the binding post 29 to form an' electric contact therewith. The lower end of the wire 31 is bent at an angle as at 32. This bent end 32 is screw-threaded at 33. and on the scrcwthrea'ded end is provided a metallic cap 34 which has internal screwthreads engaging the threaded end 33, thus the cap 34 provides an electrode which is detachable and may be removed if desired and readily replaced.

The second electrode 35 is screwed within a tapped .opening 36 in the lower end of the body portion, and the spark travels between the electrode 34 and the electrode 35. The electrode 35 is provided with a slot 37 into which. a screw-driver may be inserted for the insertion or removal of this electrode. The lower end 38 of the porcelain. 8 is provided with a series of peripheral grooves 89 which, as shown in the drawings, are annularly arranged and provide annularly projecting edges 40. The annular projections thus formed by the peripheral grooves are for the purpose of increasing the electrical resistance when the porcelain becomes coated with particles of carbon, oil, or other foreign material which is produced by the combustion within the engine cylinders, and this construction is such as to reduce the area over which the current has to traverse, thereby increasing the resistance and requiring very high voltage before current can ground before jumping the spark gap,

' trodes 34 and 35 are to each other.-

A hand lever 46 has a yoked or bifurcated end 47 terminating in arms 48 which are sullicientlyfar apart to'span the outer diameter of the sleeve 18. Each ofthesearms 48 is pivoted as at 49 to the sleeve 18, each 1 arm 48 having an. edge portion 50 designed to engage the surface 7 of the body portion 1 when the handle is moved into the position shown in Figs. 1 and 3 to move the porcelain 8 and jacket 12 longitudinally and to clamp the shoulder 15 of the jacket 12 tightly against the shoulder 6 of the body portion 1. In other words, the edges 50 act as cams to raise the jacket, with the porcelain therein, into such position as to effectively cut off the' annular passage 16 from the cavity 3. I

The porcelain 8 has a longitudinally extending passage 51, through which the wire 31 extends, and this passage is increased in diameter as at 52 to provide room for the binding post 29.

The wire 31 at its upper end may be at tached to "the binding post in any suitable manner such as by brazing or soldering, however, I preferably make the passage 52 of larger diameter than the passage ol in order to insert a sufficiently strong binding post 29.

It will be noted that with a spark plug constructed in accordance with my invention, the position of the electrodes may be changed to suit the load on the engine, or for any other reason, by merely raising the hand lever 46 to permit the edges 50.to be moved free of the surface for the body portion 1, since when the handle is in this raised position, the entire jacket and porcelain may be rotated and thus move-the electrode 34 toward or from the electrode 35 to increase or decrease the gap between said electrodes. This can be done without stopping the en gine or removing any of the" parts of the plug and may be done quickly; and easily; The indicating finger shows exactly the posi tion of the hidden electrodes, so that after the latter-have been properly positioned to give'the desired spark, the lowering ofthe hand lever 46 will lock the flange 11 againstthe shoulder 6 and create sufiicient friction to prevent vibration from the engine or other means from further changing the relative position between the electrodes.

It will thus be noted that by a simple continuous movement upwardly of the handle, and then turning the latter circumferentiallyof the jacket and porcelain, the positions of the electrodes may be changed and after the desired position is secured, a straight downward movement of the handle locks the parts in their operative position.

It will also be understood that when the hand lever 46 is in its raised position as shown in Fig. 4, the annular passage 16 which communicates with the atmosphere is in direct communication with the cavity 3. When the elements are in this position, cleaning fluid may be inserted through the passage 16 to clean the several parts.

Another valuable feature of my present invention is that the construction is such that the electrodes, while in their operative position, are confined within the cavity 3.

and are not subject to the direct carbonization which would otherwise occur it they were permitted to remain below the end of the bodv portion.

-Furthermore, by shaping the porcelain 8 as above described, the latter will remain clean for a great length of time as will also the other elements of my invention. If .it is desired to raise or lower the electrode 34 with respect to the electrode 35, it is merely cement acting to keep out moisture or particles of foreign material. The annular flange on the porcelain by being in engage- 'ment with the flanged lower end of the jacket, transmits any longitudinal pressure to the jacket, thereby relieving all strain from the porcelain. This is an extremely valuable feature of my invention, since it prevents the checking or cracking of the porcelain,

and in addition reduces the likelihood of the latter to shorten the circuit.

It will be understood that .the edge portions of'the yoked end of the' hand lever 46 act as cams to effect the movement of the jacket 12 within the body portion 1.

VVh-ile T have described my invention as taking a particular form, it will be under stood that the various parts of my invention may be changed without departing from the spirit thereof, and hence I do not limit myself to the precise construction set forth, but

consider that'I am at liberty to make such changes and alterations as fairly come within the scope of the appended claims.

Having thus described my invention, what claim as new and desire to secure by Lette rs Patent is:

'1. The combination in a spark plug, of a body portion, an electrode holder therein and including a threaded jacket and an insulating member secured therein, a sleeve adjustably secured to the jacket, and a hand lever pivoted on said sleeve and having a portion for frictional engagement with said body portion, substantially as described.

2. The combination in a spark plug, of a body portion, an electrode holder therein body portion having a recess therein reduced for a portion of its length to form a shoulder, a jacket having a flanged. end providing a shoulder movable into and out of engagement with said shoulder of the body portion, an electrode carried by the jacket, and a single band lever operative to relatively move said shoulders into and out of engagement, substantially as described.

4. The combination in a spark plug. of a body portion having a recess therein reduced for a portion of its length toform a shoulder, a ackct having a flanged end providing a shoulder movable into and out of engagement with said shoulder of the body portion, an electrode carried by the jacket, a single hand leverv operative to relatively move said shoulders into and out of engagement, said hand lever having a portion designed to lock said shoulders in their engaged position, substantially as described,

5. The combination in a spark plug, of a body portion having a recess reduced in diameter for a portion of its length to form a shoulder,a jacket having a body portion of smaller diameter than the reduced diameter of the cavity, a projection formed on said jacket having a diameter larger than the reduced cavity'and of smaller diameter than the main cavity, a hand lever pivotally supported by the ackct and having a portion for engagement with said body portion, and an electrode supported by said jacket, said hand lever being movable on its pivot to engage the body portion andjthereby force the projection on the tube into engagement with the shoulder prov1ded by said reduced recess, substantially as described.

6. The combination in a spark plug. of a body portion having a recess reduced in diameter for a portion of its length to form ins ill

'body portion having a recess rednced'in diameter for a portion of its length to form a shoulder, a jacket having a body portion of smaller diameter than the reduced diameter of the cavity, a projection on said jacket having a diameter larger than the reduced cavity and of smaller diameter than the main cavity, a member fitting within said jacket and having a portionproviding a shoulder in engagement with the inner end ol. the jacket, an electrode carried by said member, a sleeve adjustably secured to the jacket, a lever pivoted on-said sleeve and having a portion for engagement with the body portion to move the projection on said jacket into engagement with said shoulder of the body portion, a second electrode projecting into said cavity, said lever being operative to turn said jacket and member to change the relative positions between the electrodes and to lock the latter in their adjusted positions, substantially as described.

8. The combination in a spark plug, of a body portion having a recess reduced in diameter for a portion ofits length to form a shoulder, a jacket having abody portion of smaller diameter than thereduced diameter of the cavity, a projection on said acket having a diameter larger than the reduced cavity and of smaller diameter than the main cavity, an insulating member extending through said jacket and secured to the inner surface thereof, said insulating member having a depending portion extending into said cavity and an electrode extending therethrough, a binding post connecting with said electrode, an insulating cover, a member adjustable on said binding post and en gaging said cover to force the latter into engagement with the jacket and to provide a seal for the insulating member, said memher ha ing a flange in abutment with the projection on said jacket. a sleeve adj ustably secured to the jacket, a. lever pivoted on said sleeve and ha ving a portion for engagement with the body portion to move the projection on said jacket into engagement with said shoulder of the body portion, substantially as described. 7

9. The combination in a spark plug, of a body portion having a recess reduced in diameter for a portion of its length to form a shoulder, a jacket having a body portion of smaller diameter than the reduced diameter of the cavity, a projection on said j aeket having a diameter larger than the reduced cavity and of smaller diameter than the main cavity, an insulating member extending through said jacket and secured to the inner surface thereof, said insulating member having a dependingportion extending into said cavity and an electrode extending therethrough, a binding post connecting with said electrode, an insulating cover, a member adjustable on said binding post and engaging said cover to force the latter into engagement with the jacket and to provide a seal for the insulating member, said insulating member having a flange in abutment with the projection on said jacket, said jacket having a screw-threaded portion, a threaded sleeve fitting said screw-threaded portion and having a slot therein extending transversely to thejacket, and means for moving the portions or": said sleeve, formed by said slot, toward each other to bind the sleeve to the acket, substantially as described.

10. The combination in a spark plug, of a body portion having a recess reduced in diameter for a portion of its length to form a shoulder, a jacket having a body portion of smaller diameter than the reduced diameter of the cavity, a projection on said jacket having a diameter larger than the reduced cavity and of smaller diameter than the main cavity, an insulating member extending through said jacket and secured to the inner surface thereof, said insulating member having a depending portion extending into said cavity and an electrode extending therethrough, a bindinv post connecting with said electrode, an insu ating cover, a member adjustable on said binding post and engaging said cover to force the latter into engagement with the jacket and to provide a seal for the insulating member, said insulating member having a flange in abutment With the projection on said jacket, a sleeve adjustably secured to the jacket, a lever pivoted on said sleeve and having a portion for engagement with the body portion to move the projection on said jacket into engagement with said shoulder of the body portion, said insulating member having a plurality of pe ripherally extending grooves providing air nularly extending projections, substantially as described.

11. The combination in a spark plug, 01'' a body portion having a recess therein reduced for a portion of its length to form a shoulder. a jacket having a flanged end providing a shoulder movable into and out of engagement with said shoulder of the body portion, an electrode carried by the jacket, and means operative to relatively move said shoulders into and out of engagement, substantially as described.

diameter for a portion of its length to form a shoulder, a jacket having a body portion rotatable within and of smaller diameter than the reduced diameter of the cavity, said jacket being provided with a projection having a diameter larger than the reduced cav ity and of smaller diameter than the main cavity, a hand lever movably supported by the jacket and having a portion for engagement with-said body portion, and an electrode supported by said jacket, said hand lever being movable on its support to engage the body portion and thereby force the projection on the jacket into engagement with the shoulder provided by said reduced re-- cess, substantially as described.

14. The combination in a spark plug, of a body portion having a recess reduced in. diameter for a portion of its length to form a shoulder, a jacket having abody portion of smaller diameter than the reduced diam- ,cter'of the cavity, a projection on saidjacket having a diameter larger than the reduced cavity and of smaller diameter than themain cavity, a member fitting within said jacket and having a portion providing a shoulder in engagement with the inner end of the jacket, an electrode carried by said member, a sleeve adjustably sccuredto the jacket, a"

v name to this specification in the two subscribing witnesses.

lever movably mounted on said sleeve and having a portion for engagement with. the body portion to move the projection on said jacket into engagement with said shoulder of the body portion, substantially as described. 15. The combination in a spark p1ug, of a body portion having a cavity reduced in diameter for a portion of its length producing a shoulder, a jacket of smaller diameter than the reduced portion of the cavityantl having an annular flange designed to engage said shoulder, an electrode carried bv said jacket, and means including a; cam for actuating said jacket to move its flange into and out of contact with said described.

16. The combination in a spark plug, of a body portion, an electrode holder therein in cluding a jacket and an insulatin member therein, means on said jacket forming a support, and a hand lever movably mounted on said support and havin a portion for en'- gagement with said b0 y portion,'substantially as described.

17. An electrode holder for spark plugs including a body portion for insulatin material having-an annularly projecting ange and a portion depending from said flange, said depending portion having a plurality' of peripherally extending grooves providing annularly projecting edges, said grooves being curved in cross section, substantially as described. v

In testimony whereof I have signed my U presence of shoulder, substantially as wriLLiAM s. rnoiuas. Witnesses I RHODA E. GILLIES, CHAS. E. Poms. 

